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NUTRIENT LOSSES FROM TIMBER HARVESTING
IN A LARCH I DOUGLAS-FIR FOREST
NELLIE M. STARK
USDA FOREST SERVICE RESEARCH PAPER INT-231
INTERMOUNTAIN FOREST AND RANGE EXPERIMENT STATION
FOREST SERVICE, U.S. DEPARTMENT OF AGRICULTURE
USDA Forest Service
Research Paper INT-231
July 1979
NUTRIENT LOSSES FROM TIMBER HARVESTING
IN A LARCH/DOUGLAS-FIR FOREST
Nellie M. Stark
INTERMOUNTAIN FOREST AND RANGE EXPERIMENT STATION
Forest Service
U.S. Department of Agriculture
Ogden, Utah 84401
THE AUTHOR
Nellie M. Stark is a forest ecologist with the Montana Forest
and Conservation Experiment Station, University of Montana, School
of Forestry at Missoula, Mont. She has studied nutrient cycling in
temperate and tropical forest ecosystem for many years. She is the
author of the direct-cycling theory and also the concept of the
biological "life" of soils--a means of evaluating the rate of
deterioration of the productivity of soil.
ACKNOWLEDGMENTS
The author is grateful to the USDA Forest Service Intermountain
Forest and Range Experiment Station, for the support of this work.
Special thanks are due to program manager Ron Barger (Forest Residue
Utilization Program, Forest Sciences Laboratory, Missoula, Mont.)
for coordinating the many aspects of this study, and for his encouragement. Joyce Schleiter, Robert Benson, Al Harvey, Dave Fellin,
Wyman Schmidt, Ray Shearer, Roger Hungerford, and Jack Schmidt of
the Forest Service, and Robert Steele and Howard Newman of the
School of Forestry, University of Montana, all helped make the
study productive. In our laboratory, Paul Pawlowski and Maggie
Catalfamo helped immeasurably with the work.
.I
RESEARCH SUMMARY
Studies of the total amount of biologically essential nutrients
removed in logs and water through clearcutting, shelterwood cutting,
and group-selection cutting were conducted in a western larch (Larix
occidentalis)/Douglas-fir (Pseudotsuga menziesii) forest at the
Coram Experimental Forest near Glacier Park, Montana. Nutrient
removal by species was investigated under three intensities of
harvest.
Results show that with the most intensive logging method
(clearcutting) less than 0.25 percent of the total content of eight
biologically essential cations in the effective root zone were
removed with wood and bark. This means that intensive harvest took
away an equivalent of 1/4 of 1 percent of the nutrients stored in
the soil and rock of the rcot zone.
In theory, it would require
28,000 years of clearcutting on a 70-year rotation to exhaust the
total nutrients in the present root zone. Soil development will
slowly extend the root zone downward.
Far more important than total
nutrients are those nutrients available in the soil.
Harvest of wood
and bark removed an equivalent of less than 14 percent of most of
the available elements in the root zone. Harvest is a one-point-intime removal of nutrients that have been accumulated in the wood and
bark of trees over 70 years time.
Removal of only 14 percent of
what is at one moment available in the soil is a smail loss. Unfortunately, we cannot yet measure the weathering rate so we cannot
estimate how rapidly the removed nutrients will be returned through
weathering. Harvest did remove from 14.8 to 91.7 percent of the
available zinc in the soil (accumulated over +70 years). Although
zinc is scarce in the parent material, this loss is not serious
because sufficient zinc is still available for seedling growth.
In
most cases bulk precipitation alone will return all of the nutrients
removed in harvest within 70 to 100 years. Nutrient losses from
harvest on this relatively young, fertile soil is not a problem to
management in the absence of erosion.
Nutrient levels in an intermittent stream were virtually
unchanged by all logging treatments. The skyline system did not
cause erosion. Because the area does not have a permanent stream
or impermeable bedrock, it is unsuited to typical watershed study
methods. Water samples taken below the root zone did show nutrient
losses as a result of harvest, but these were at levels not significant to management. The most severe treatment studied, clearcutting by skyline and light burning, did not cause serious nutrient
depletion from this forest ecosystem.
CONTENTS
Page
INTRODUCTION
1
INFLUENCE OF LOGGING ON SOIL WATER NUTRIENTS
4
Methods
Results and Discussion
INFLUENCE OF WOOD REMOVAL ON NUTRIENT CYCLING
Methods
Results and Discussion
4
6
16
16
17
CONCLUSIONS
25
APPLICATIONS
26
PUBLICATIONS CITED .
27
APPENDIX A .
29
Plant Species Found on Coram Forest .
31
APPENDIX B .
33
APPENDIX C . .
37
INTRODUCTION
Modern logging methods are progressing toward complete utilization of wood fiber.
With greater utilization comes increased removal of biologically essential nutrients.
On rich soils, nutrient loss may do little harm, but on old or very young, poorly developed soils nutrient depletion caused by harvest may create either temporary nutrient
shock or long-term nutrient deficiencies. In the case of nutrient shock (depletion of
available nutrients), the soil contains adequate levels of biologically essential elements but they are in unavailable form. During shock, one or more of the essential elements is depleted from available form, and time is needed to allow weathering, precipitation, and organic decomposition to restore the available nutrient reserves. Long-term
nutrient deficiencies result when not enough of one or more biologically essential elements remains in the root zone of the soil in either available or unavailable form to
restore the soil to productivity (Stark 1977, 1978).
In western Montana, the greatest concern is for temporary nutrient depletion of
young, undeveloped soils. Steep topography can accelerate nutrient loss through runoff,
erosion, dust, or slump. In calculating nutrient losses resulting from harvesting, data
are often not available for various species or different harvesting intensities.
This study has accumulated data on the elemental content of the harvestable portions of eight local tree species. Actual nutrient loss from the site was estimated
from careful measurement of the volumes and weights of each species harvested. Harvest
losses were related to the levels of available and total biologically essential elements
in the soil to the limit of the root zone.
Land managers have also shown increasing concern over the possible loss of nutrients in soluble form from the root zone as a result of harvest. Erosion and solution
losses below the root zone can detract from the ability of a soil to grow the next forest. Where logging activities approached streambanks too closely, there has been an
increase in the sediment load and nutrients lost via streams. The Hubbard Brook study
(Bormann and others 1968) showed the magnitude of nutrient loss associated with clearcutting. Few studies have attempted to quantify loss of soluble nutrients on drier
western soils where the streams are intermittent and the bedrock fractured. Loss of
soluble nutrients must be understood to allow ecologically sound land management.
Numerous studies have monitored the effects of logging and fire on stream water
quality (Fredriksen 1971, Fredriksen and others 1975; Likens and others 1967; Moore
1974; Tiedemann 1974). Watershed studies are conventionally used to show changes in
water quality as a result of treatment. But the stream studied in the Coram Experimental Forest is partly underground. It is ephemeral and the area does not have unfractured bedrock, making it unsuited to a conventional watershed study. For this
reason, nutrient losses below the root zone were measured using lysimetry and tension
soil water extractors. Nutrients lost below the root zone of a mature forest are almost
as effectively lost to tree growth as if they were washed into a stream.
In 1973, the USDA Forest Service initiated a series of timber harvesting and utilization studies on the Coram Experimental Forest near Glacier National Park in western
Montana (fig. 1). The overall objective of the project was to evaluate four levels of
utilization and three silvicultural prescriptions, followed by burn and no-burn treatments, on the recovery of the above and below ground portions of the ecosystem. The
study reported here, a portion of the total project, describes the impact of different
levels of log removal and solution losses on the nutrient status of the ecosystem.
1
CORAM
EXPERIMENTAL
FOREST
EiJ BROADCAST BURNED
0 UNBURNED
CLEAR CUT
.: ··,·:··-
1
N
Scale:
0
I
0
I
200
1000
I
f
I
400
2000 FEET
I
I
600
METERS
Figure 1.--Map of the Coram Experimental Forest logging study sites (from Artley and
others 1978).
The treatments were designed to study the effects of different degrees of fiber
utilization and burning 1 year after logging. The study involved 12 scientists and
covered the period 1 year prior to logging (1973-74), logging (May-September 1975),
burning (September 1975), and 2 years thereafter.
2
The forest is composed of larch/Douglas-fir (Larix occidentalis Nutt./Pseudotsuga
menziesii [Mirb.] Franco) on steep slopes (35-45 percent) from 3,339 to 6,269 feet
(1,018 to 1,942 m) elevation. The mean annual precipitation at the lower stations
averages 31 inches (787 nm1), with a mean annual temperature of 42.8°F (6°C). Much of the
precipitation falls as snow. The snowpack lasts about 6 months. Appendix A includes
a habitat type listing and a species listing for herbs and shrubs. Soils are derived
from argillite, impure limestone, and quartzite, with some influence from glacial drift
and in some areas volcanic ash (Klages and others 1976). Most are gravelly silt loams
with up to SO percent rock. Surface soil had a bulk density of 0.9 g/cm 3 . The soils
of the study area are primarily cryocrepts of the Felan series (possibly andeptic), and
andeptic cryoboralfs, or eutroboralfs.
A portion of the main study included a complete inventory by the USDA Forest Service
of all standing dead and live timber, as well as downed timber before and after harvest. 1
The difference constitutes the material removed from the site during harvest.
The silvicultural prescriptions included two replications of clearcutting, shelterwood, and group selection logged with a skyline yarding system. Treatments within each
prescription were (descending order of intensity of utilization) as follows:
Silvicultural
prescription
Clearcut (CC)
1 and 2
Remaining
understory
treatment
Utilization
standard
Postharvest
site preparation
1. Intensive log utilization
(8ft long, 3 in top, 2.4 m-7.6
em) all trees live and dead.
Cut
Broadcast burn
2. Conventional sawlog utilization of live and recently
dead sawtimber.
Cut
Broadcast burn
3. Heavy fiber utilization of
all trees 1+ india. (2.54 em),
live and dead, including tops
and branches 1+ in (2.54 em).
Cut
None
4. Intensive log utilization
(8 ft, 3 in top, 2.4 m-7.6 em)
all sawtimber (7+ india.,
17.8 em), live and dead.
Uncut
None
Shelterwood (SW)
1 and 2
Same as for clearcuts for all categories
Group selection
(GS) 1 and 2
Same as for clearcuts for all categories
Control (C)
1 and 2
Unlogged, unburned
1 Benson,
R. E., and Joyce Schleiter. 1978. Volume and weight characteristics of
a typical Douglas-fir/western larch stand. USDA Forest Service, unpublished report.
3
INFLUENCE OF LOGGING ON SOIL WATER NUTRIENTS
Methods
Skyline logging studies in Douglas-fir/larch forests at the Coram Experimental
Forest in western Montana used clearcutting and shelterwood cuts, with three levels of
utilization (reported here). Because the area does not have a permanent stream, nutrient loss was measured in the ephemeral Abbott Creek and through changes in the soil
water quality below the root zone. The elements H, Ca, Cu, Fe, F, Mg, Mn, Na, N0 3 , P0 4 ,
and Zn were measured in soil and stream water, in precipitation, and throughfall whenever water was available before and after logging and 1 year after burning.
The study reported here covers only the nutrient cycling portion of the main
research. Only the clearcut and shelterwood areas were studied for soil water quality
and the fourth treatment (understory uncut, slash left, no burn) was omitted from consideration to focus attention on extreme treatments.
Changes in soil chemistry were studied by soil extraction using 0.002N H2 S0 4 and
by soil water extracted from soil in the field using permanently placed tension extractors (Soil Moisture Corporation). Soil and water samples were from replicate plots on
clearcutting and shelterwood treatments. Soil samples were obtained by digging a pit
to 19.6 inches (50 em) and removing 4,000 g soil samples at 0-3.9 inches (0-10 em),
7.8-9.8 inches (20-25 em), and 17.7-19.6 inches (45-50 em) depth. The soil samples
were then taken to the laboratory, sieved (1 mm), and 2 g subsampl.es were extracted
with 0.002N H2 S04. The cations were analyzed on an atomic absorption spectrophotometer
(Techtron AA-5). Phosphate was determined colorimetrically on the acid extract (Farber
1960). Soils were also tested for physical characteristics. Soil water samples were
extracted from sites 3 feet (1 meter) from the soil pits (fig. 2) by placing a 1-1/2
inch (3.8 em) plastic tube with a porous ceramic tip in a carefully augered 1-1/2 inch
hole to 19.6 inches (50 em). The porous ceramic tip was previously cleaned with acid
and distilled water. The tip was seated in a slurry of mud from the bottom of the
hole and sealed along the sides of the hole to prevent air leaks. After a period of
5-10 days for equilibration, the PVC tubing was sealed with a stopper and a vacuum was
pumped on the tube, drawing soil water in through the ceramic tip. After 3-5 days,
soil water was removed from the tubing using a clean pump and acid-cleaned Nalgene
tubing and bottles. This water was taken in marked bottles to the laboratory for chemical analysis on the atomic absorption spectrophotometer and colorimeter.
The two methods, laboratory soil extraction and field soil water extraction, were
used to compare results. Soil water removed under tension was by far the best indicator of changes in soil chemistry. The soil water is the solution in immediate contact
with living roots and from which roots obtain nutrients. It is not an artificial
extract. The soils vary greatly from point to point, so a soil water sample gives
integrated results. Therefore, only soil water data will be reported here. Samples of
soil water were withdrawn from above the tree root zone, within the tree root zone, and
below the tree root zone whenever available soil water occurred. Fractured rock occurs
at 19.6-21.7 inches (50-55 em) depth. The data presented here represent the results
from 200 soil water probes over 4 years. Bulk precipitation, stream water, and throughfall were collected from the same areas. Abbott Creek is ephemeral and partly underground, so it could not be used directly in evaluating nutrient losses from the treatments. It surfaces above one of the treated areas, and then goes underground below the
clearcut and emerges near the shelterwood cuts. Changes on the slopes could be reflected
in the stream, in spite of its ephemeral nature.
4
Figure 2.--Soil water probes set at three depths in the ground to collect soil water
after the burns at Coram.
Water samples had to be frozen because of the distance between the laboratory and
field study site. The samples were normally frozen for 1 week, thawed at room temperature, and analyzed by a Techtron AA-5 atomic absorption spectrophotometer for Ca, Cu,
Fe, K, Mg, Mn, Na, and Zn (Techtron 1974). Subsamples were tested for pH, F, and N0 3
by specific ion analyzer, and P0 4 by the most sensitive stannous chloride method reported
in Farber (1960). Data from other portions of the study were used to aid in the final
interpretation. Because water samples could rarely be brought from the field in winter
without freezing, it was impossible to measure bicarbonates.
Statistical tests compared the changes in the elemental content of soil water means:
1.
By depths and treatments--total cations and anions
2.
By year and treatments--total cations or anions
3.
By silvicultural prescription and utilization standard--total cations or
anions
4.
By all three methods above for individual cations and anions
5.
By control blocks versus test blocks and by test versus test blocks.
The F-statistic was used first to test for equal variances in each paired comparison. Where the variances were found to be equal, a regular t-test was used to test for
the differences in the means; an "appropriate" t-test was used.
5
.·.
~ '
.:..~ •,: .,
Results and Discussion
All results are expressed as significant at the 5 percent level. Data are reported
for pretreatment (July 1973-April 1974, 237 collections), postlogging (May 1974-Sept. 1,
1975, 452 collections), and 1-year postburn (Sept. 1, 1975-June 30, 1976, 870 collections). About 510 collections were made in 1978.
The initial statistical tests showed that the replicates for each silvicultural prescription differed significantly in soil water quality so that the two clearcuts and
two shelterwood treatments had to be considered separately. Comparisons were made
between the test area and its nearest unlogged control (table 1). Appendixes Band C
provide detailed soil physical and chemical data, which may be compared to soils elsewhere and which may be useful in management plans.
Table I.--Mean and standard deviation of total cations and anions in soil water after
logging and after burning, Coram logging study (mg/£)
Study
plot
Postlogging treatment
1
2
3
Postburn treatment
1
2
3
Total cations
Control 11
Mean
SD
21.8
16.3
21.8
16.3
21.8
16.3
22.3
10.9
22.3
10.9
22.3
10.9
Control 2
Mean
SD
7.1
3.2
7.1
3.2
7.1
3.2
9.0
3.9
9.0
3.4
9.0
3.9
Shelterwood 1
Mean
SD
13.9
6.5
14.9
8.2
12.1
6.3
14.5
5.0
14.3
9.0
12.9
6.1
Shelterwood 2
Mean
SD
19.4
10.2
9.2
4.4
15.1
15.6
17.3
7.5
10.8
5.3
11.4
9.1
Clearcut 1
Mean
SD
17.2
10. 7
34.3
26.7
19.6
12.8
25.1
13.5
41.5
28.4
22.1
17.6
Clearcut 2
Mean
SD
17.3
10.7
7.9
4.9
11.9
6.7
17.2
11.9
16.2
11.9
11.9
6.7
Control 1
Mean
SD
1.9
.9
1.9
.9
1.9
.9
7.5
5.2
7.5
5.2
7.5
5.'2
Control 2
Mean
SD
1.4
.6
1.4
.6
1.4
.6
2.6
4.9
2.6
4.9
2.6
4.9
Shelterwood 1
Mean
SD
2.2
1.3
5.6
9.3
2. 1
1.4
4.8
5.1
3.9
3.6
4.9
4.6
Shelterwood 2
Mean
SD
1.9
.8
1.3
.7
1.3
.5
6.4
6.4
7.1
6.9
3.8
2.9
Clearcut 1
Mean
SD
5.3
3.5
14.2
15.9
6.5
5.5
19.6
15.9
31.2
25.0
5.5
5.4
Clearcut 2
Mean
SD
3.3
5.0
1.4
•5
3.0
2.6
19.9
19.4
14.3
12.3
3.0
2.6
Total anions
1 Controls 1 and 2 are the same plots for treatments 1, 2, and 3.
Treatment 1 =
heavy log utilization, light burn, Treatment 2 = conventional utilization, medium burn,
Treatment 3 = heavy fiber utilization.
6
.. :·
Shelterwood Logging--Cation Losses
The total cations in the soil water for shelterwood 1 were lower 1 and 2 years
postlogging when compared to the closest control. Shelterwood 2, which was about 0.31
miles (0.5 km) from shelterwood 1, had higher cation levels in the soil water for treatment 1 postlogging, and treatments 1 and 2 (light and hot burns) postburn (table 1).
The total soil water cations in shelterwood 1 probably result from unusually high
levels of ions in the soil water of the control, which had unusually deep litter.
Shelterwood 2 behaved more as expected (table 1), with higher cation loadings in the
postlogging and postburn soil, compared to its nearest control (control 2, table 1).
Standard deviations are sometimes high because data cover a full year's seasonal
variation.
Clearcut Logging--Cation Losses
Clearcut 1 was the only block where a moderately hot burn treatment was possible.
It produced a significant increase in the soil water cations, compared to its closest
control (1). Logging left considerable needle debris on the slopes, which produced
postlogging increases in the soil cations of clearcut 1, and postburn increases from
nutrients added from ash. Clearcut 2 had higher total cation levels in the soil water
following logging where the slash was removed and later burned (treatment 1) and
where it was removed and not burned (treatment 3) but not in treatment 2. The removal
of slash left a large amount of fine needle debris so that all sites had abundant
fungal growths during the winter under the snow, regardless of whether the coarse
slash (3 in, 7.6 em) was removed or not. After burning, clearcut 2 had higher soil
cation levels than its control for all treatments, heavy and light burning, and no
burning (table 1).
Shelterwood Logging--Anion Losses
The total anions in the soil water of shelterwood 1 were higher 1 year postlogging
on the heavy slash site (treatment 2, table 1), but lower than the control 2 years
postlogging. In the case of shelterwood 1, "postburn" actually means 2 years postlogging, because this block was never burned. Shelterwood 2 was burned, and showed
high levels of anions in the light burns but not the hot burns (postburn) and only
in the heavy slash loading postlogging (compared to controls). High anion levels on
the high utilization unburned site must come from the decay of excess needles.
Clearcut Logging--Anion Losses
Clearcut 1 had significantly higher levels of total anions in the soil water
(mostly N03-N) following logging in all three treatments, compared to the soil water
from controls. This means that slash decomposition during the first year following
logging resulted in an unusually high rate of nitrate release relative to the controls.
Postburn, the anions were high in treatments 1 and 2 (light and heavy burns). Clearcut 2 showed elevated levels of anions only in treatment 3 (slash removed), but in all
three treatments postburn (table 1). The main anion is again nitrate.
Total Cation and Anion Losses by Slash Treatment
The effects of the three slash treatments on total soil water cations can be seen
by comparing treatment means within years. For total cations, all depths combined,
treatment 1 (slash removed, burned) was different from treatment 2 (slash left, burned)
in four out of eight possible cases. Treatments 1 and 3 differed in two out of eight
cases, and treatments 2 and 3 differed significantly in three out of eight cases.
7
No one treatment produced predictable increases in soil water cations in more than 50
percent of the tests. This is partly the result of the moderate disturbance of the
site from the logging method (skyline) and the relatively low burning temperatures
(138°F, 59°C).
The total anions differed significantly between treatments 1 and 2, and treatments
1 and 3 four out of eight times (each) and between treatments 2 and 3 in six out of
eight cases. The heavy burn did produce significant increases in the anions and particularly nitrate in soil water.
Results by Individual Ions
The analysis of the results for individual ions requires considerable space, therefore only a few main points will be presented in a year-to-year comparison. The elements
N0 3 , Mg, Cu, Na, Zn, and Mn were those most often influenced by logging and burning
(table 2). Those most influenced by burning alone were N03-, Cu, Mg, Mn, K, Fe, Zn,
and P0 4 . Those least influenced by the treatments were Ca, F, and Fe. These are
strongly dependent on an acid soil solution for solubility. In most cases the alkali
added to the soil through burning was inadequate to cause a greater increase in soil
alkalinity as had occurred in a previous study (Stark 1977). If the burns had been
hotter than 572°F (300°C), these elements, and particularly Fe, should have been significantly altered by the burning. The average ion concentrations in soil water are shown
in table 3.
Table 3 shows the average levels of cations and anions present in soil water before logging and after burning. Unfortunately, during 1973-74, or prelogging, no data
could be obtained from shelterwood 2, clearcut 2, and control 2. These results summarize
the effects of increasing utilization for all four areas compared to the two controls
(table 3). Most elements in the soil water do not show drastic differences between prelogging and postburn samplings. There is a tendency toward more No 3-N and P0 4 after
burning, but only in a few cases are the differences great. Significant differences
that appear in the raw statistics may not appear in these summaries. The summaries are
included to show the low magnitude of chemical differences in soil water resulting from
logging and light burning.
Shelterwood cutting
tant differences between
Shelterwood 1, which was
water ion concentrations
caused the greatest changes in phosphate with the most imporpostlogging and postburn treatments 1 and 2 for shelterwood 2.
not burned in 1975, had almost no significantly different soil
2 years postlogging.
Clearcutting showed no definite pattern of elemental differences in the soil water
following logging, but treatments 2 and 3 were most different (by seven elements on
clearcut 1, but not on 2). Burning produced significant differences in 10 ions between
the medium burn (treatment 2) and slash removal (treatment 3) postburn for clearcut 1 but
not for 2. Clearcut 1 generally burned much hotter than did 2.
Ionic differences by depth were most prominent between 7.9-9.8 inches (20-25 em)
and 15.7-19.6 inches (40-50 em) when all 3 years were considered collectively. This is
surprising because the burning and logging should have caused the greatest change at
0-3.9 inches (0-10 em). The importance of deep soil differences in ion content suggests
a spotty but widespread influence of scattered limestone deposits beneath the soil
surface.
The means in tables 1 and 3 are figured on a slightly different number of sample
points, so they do not agree exactly.
8
tests~
practice~
Table 2.--Summary of resuZts of year-to-year statisticaZ
aZZ soil depths and separating siZvicuZturaZ
and site preparations
Year 1
Ca
Cu
Fe
F
Element
Mg
Mn
K
N03
Na
combining means for
level of utilization~
P04 :Zn:Cations:Anions
Years 1 vs 2
*2
Control 1
Shelterwood 1
Heavey log util.
light burn
Conv. log util.
med. burn
Heavy fiber
uti 1. --no burn
Clearcut 1
Heavy log util.
light burn
Conv. log util.
med. burn
Heavy fiber
util.-no burn
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
Control 2
Shelterwood 2
Heavy log util.
light burn
Conv. log util.
med. burn
Heavy fiber
util. -no burn
Clearcut 2
Heavy log util.
light burn
Heavy fiber
util. -no burn
Year 1 vs 3
Control 1
Shelterwood 1
Heavy log util.
light burn
Conv. log util.
med. burn
Heavy fiber
util.-no burn
*
*
See footnotes at end of table.
*
*
*
*
*
*
*
(Cont.)
9
Table 2.--Summary of results of year-to-year statistical tests~ combining means for all
soil depths and separating silvicultural practice~ level of utilization~ and
site preparation--Continued
Year 1
Clearcut 1
Heavy log util.
light burn
Conv. log uti 1.
med. burn
Heavy fiber
util.-no burn
Ca
Cu
*
*
Fe
F
K
*
*
*
*
*
Element
Mg
Mn
P04: Zn:Cations:Anions
N03:
Na
*
*
*
*
*
*
*
*
*
*
*
Control 2
Shelterwood 2
Heavy log util.
light burn
Conv. log util.
med. burn
Heavy fiber
util.-no burn
Clearcut 2
Heavy log util.
light burn
Conv. log util.
med. burn
Heavy fiber
util.-no burn
Years 2 vs 3
Control 1
Shelterwood 1
Heavy log util.
light burn
Conv. log util.
med. burn
Heavy fiber
util.-no burn
Clearcut 1
Heavy log util.
light burn
Conv. log util.
med. burn
Heavy fiber
util.-no burn
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
See footnotes at end of table
(Cant.)
10
Table 2.--Summary of results of year-to-year statistical
soil depths and separating silviculti~al
site preparation--Continued
tests~
practice~
combining means for all
level of utilization~ and
Element
Year 1
:Ca
Cu
Control 2
*
*
Shelterwood 2
Heavy log util.
light burn
Conv. log util.
med. burn
Heavy fiber
util. -no burn
Clearcut 2
Heavy log util.
light burn
Conv. log util.
med. burn
Heavy fiber
util. -no burn
Fe
F
K
Mg
*
*
*
*
*
*
-*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
P0 4 :Zn:Cations:Anions
Mn
*
*
*
*
*
lyear 1 - prelogging,
Year 2 - postlogging,
Year 3 - postburn.
2* indicates a significant difference at the 5 percent level.
11
*
*
N
I-'
2
3
Clearcut 1
. 05
. 05
. 05
8.9
7.9
5.3
13.8
4. 7
. 13
5.00
.39
.05
.35
1
2
3
Clearcut 2
Control 1
Control 2
. 04
. 03
. 04
15.0
24.3
16.3
. 08
. 03
.06
1
2
3
C1earcut 1
. 04
.06
.06
. 04
. 04
7.7
4.2
6.5
.15
. 17
1. 90
. 06
.03
. 04
. 03
1
2
3
--
. 04
. 03
Shelterwood 2
14.2
--
0.04
.03
8.1
7. 1
8.3
12.3
12.9
--
:
: Cu
0.10
.10
. 09
9.8
7.5
---
-6"
:
: Ca
1
2
3
:
li+XlO
Shelterwood 1
One Year Postburn
Control
2
3
Shelterwood 1
Prelogging
Block
Treat- :
ment :
:
:
.13
.19
.15
.13
.14
.08
. 04
.16
.12
.13
.13
.17
.16
.12
.19
.15
.27
0.25
.16
: Fe
:
5.2
12.5
2.2
5.9
5.5
4.0
5.0
2.2
.38
.64
.31
. 08
.21
. 09
.12
. 09
7.2
4.7
3.6
.11
.06
.10
3.5
7.2
2,9
4.9
3.4
K
4.4
4.2
3.9
:
.15
. 09
.16
.12
.18
. 09
0.09
.10
F
2.4
1.0
2.5
1.8
1.3
2.3
4.2
2.1
2.5
1.4
2.3
1.7
1.5
1.7
1.9
2.4
1.8
.005
.009
.01
.16
.01
. 01
. 01
. 01
. 04
. 04
.18
. 01
.01
.01
. 02
.03
.02
0.06
.02
6.3
2.3
16.7
12.8
6.8
16.9
28.6
5.1
5.0
5.9
3.0
3.5
2.9
4.4
2.5
5.4
2.9
3.6
1.8
:
:
:
2.1
2.1
:
: N0 3
Element
: Mg : Mn
burning (1975-76)
.8
.6
.7
.8
.5
.7
.7
.5
1.0
.6
.6
0.8
.8
.9
--
--
--
---
Na
:
:
.37
.27
.81
.80
.55
.87
.75
.37
.74
.53
.54
.94
.62
.49
.13
.54
.29
0.33
.23
P0 4
.02
.03
17.6
13.8
7.4
6.8
2.6
18.3
16.3
11.3
22.2
8.8
17.9
29.6
5.7
23.4
41.9
21.4
.02
. 02
.03
.06
.05
.04
5.8
6.5
3.7
4.6
3.6
5.1
18.7
11.2
13.3
15.3
13.7
15.0
.04
.02
.03
.03
.03
.03
.03
.04
.04
0.04
.03
Total
Zn :Cations :Anions
Table 3.--Average elemental content of Coram soil water by silvicultural treatment before logging (1973-74) and after
·;
Ionic Differences in Soil Water by Years
The total cations in the soil water showed few significant differences by year,
but the total anions were significantly different between years 2 and 3 (logging and
burning) in shelterwood 1, 10 out of 14 plots. Copper, potassium, magnesium, nitrate,
sodium, and phosphate were the ions most influenced by burning between years 2 and 3.
Logging, as measured by ion changes between years 1 and 2, produced fewer ionic differences than did burning. Those ions most affected by logging (based on annual comparisons) were F, Mg, Mn, N0 3 , Na, and Zn. These were probably released from extremely
active needle decay during the winter.
The exceedingly dry summer of 1977 complicated this study. Only a very few soil
water samples could be extracted at all, and these were taken in the early spring. So
few samples of soil water are available from 1977 that it is impossible to tell anything
about nutrient movement for that year. It is quite certain that very little water or
nutrients moved below the root zone in 1977.
In 1978, more than 450 soil water samples were collected during the spring. For
purposes of comparison, data were taken from the months of May and June for 1978 and
compared to data from May and June of 1976, the last year with collectable soil water.
Data were combined for all depths within treatments for each block studied. Results are
summarized in the following tabulation:
Significant
ion
Year UJith
greater quantity
Block
Treatment
Shelterwood 1
Unburned
Light fuel
Ca
Cu
Zn
78
78
78
Shelterwood 1
Unburned
Heavy fuel
Cu
Fe
F
N03
Zn
78
78
78
76*
78
Shelterwood 1
Heavy utilization
No burn
Cu
Fe
F
N03
Zn
78
78
78
76*
78
Clearcut 1
Heavy fuel
Burned
Cu
Fe
F
N0 3
Zn
78
78
78
76*
78
Clearcut 1
Heavy utilization
Unburned
F
Mn
N03
Na
78
76
76
76*
76
Cu
F
N03
Zn
78
78
76*
78
Control 1
K
No treatment
13
Continued
Block
Significant
ion
Treatment
Year with
greater quantity
Shelterwood 2
Light fuel
Burned
Fe
F
N0 3
Zn
78
78
76*
78
Shelterwood 2
Heavy fuel
Burned
Ca
Cu
Fe
F
N0 3
Zn
78
78
78
78
76*
78
Shelterwood 2
Heavy utilization
Cu
Fe
F
N0 3
Na
Zn
78
78
78
76
76*
76
78
Mn
Clearcut 2
Light fuel
Burned
Fe
F
N03
P04
78
78
76*
76
Clearcut 2
Heavy fuel
Burned
Fe
F
N03
Zn
78
78
76
76*
78
Mn
Clearcut 2
Heavy utilization
Ca
Fe
F
Mg
N03
Na
Zn
78
78
78
78
76*
78
78
Control 2
No treatment
Ca
Cu
F
Mg
Mu
Zn
78
78
78
78
78
78
*N03 consistently higher in 1976.
14
These results are extremely difficult to interpret because the 1978 soil water
represents those nutrients freed from the surface and through weathering in 1977 and
in 1978, minus what was taken up by plants. Normally, nutrient status is best evaluated
year by year, but this is impossible with this method in dry soil. Theoretically, low
available soil moisture during the growing season in 1977 should mean abnormally low
nutrient uptake from the soil and slow growth. Increment borings of trees in the area
do verify slow growth for 1977, but there is no proof of low uptake. If the roots did
not take up their "normal" amount of water and nutrients in 1977, then there would be
a natural excess of nutrients in available form at the start of 1978. These extra
nutrients would appear in the extracted soil water in 1978 and we would not know if they
were "a leftover excess" from 1977, or if they truly resulted from the treatments
applied.
Soil moisture in July of 1977 was 7.8 percent and only 8.4 percent in the wettest
period of the summer. Based on the -1/3 and -15 bar moisture contents for these soils,
a summer moisture percentage of 7.8 percent would allow little or nothing for plant
uptake and growth in July. Thus, most nutrient and water uptake had to occur in May
and June of 1977. The trees apparently lost 1.5 months of growth water in 1977. From
these results, it is fair to say that some nutrients were left in the soil after the
1977 growing season in excess of the "usual" levels after a full growth period. High
nutrient levels in 1978 would be expected under these conditions. We still do not know
for sure if nutrient levels were elevated in 1978 because of treatment inputs or not.
The magnitude of differences in means from 1976 and 1978 is small enough to suggest that
if treatment was also causing higher soil water nutrient levels, it was probably not a
major addition of great significance to management. In a few. cases the means for
individual ions in the 1978 soil water were two to three times higher than for 1976,
but in the majority of cases, the difference of means was much lower. Copper and zinc
were often two or more times higher in the soil water in 1978 as compared to 1976.
Because this difference appears in the control plots also, it is likely that the increase
in these ions in soil water is the result of some widespread release after the soil
became moist again and not of the treatments alone.
Not all ions were higher in 1978 than in 1977. Potassium and magnesium were only
higher in a few cases. Potassium did not show up as significantly higher (5 percent)
in the 1978 soil water from any of the hot or lighter burns, suggesting that burn treatment effects had disappeared. Sodium was higher in 1978 than in 1976 in only 3 out of
14 plots. Copper and zinc were higher in 1978 soil water in 8 out of 14 plots; zinc,
in 11 out of 14 plots, respectively. P0 4 was highest in 1978 soil water in only 1 out
of 14 plots (clearcut 2, light burn).
Nitrate was higher in 1976 soil water compared to 1978 soil water in 11 of 14 plots.
Nitrate was often two to five times higher in 1976 than in 1978, which suggests treatment
effects forcing the soil nitrate levels higher in 1976. Because nitrate is the only ion
that is produced in the soil mainly by microbial activity, it could be expected to behave
the opposite of ions weathered from rock. Ion release from organic matter is all microbial, but additions of nitrate to the system are dependent on both temperature and moisture. It is likely that the low soil moisture in 1977 resulted in less nitrogen fixation
than would occur in a wetter year. Thus, the soil water would be readily depleted of
available No 3 -N in 1978 when active plant growth began. Only the light burn area in
clearcut 1 showed no significant ion differences in soil water between 1976 and 1978.
Control 2 showed 6 out of 10 ions higher in 1978 than 1n 1976, again suggesting that
these high ion concentrations were the result of drought rather than the treatments.
Control 1 had fewer significant ions in the 1978 soil water as compared to control 2,
but control 1 had much less litter and different soil moisture conditions than occur at
higher elevation.
In general, the effects of logging and fire appear to be small 4 years after logging and 3 years after light burning.
15
Clearcutting had a greater impact on soil nutrients than did shelterwood cutting,
although neither produced massive or serious nutrient losses. Burning, as expected,
increased the concentration of most ions in the soil water, especially Cu, K, Mg, Na,
N0 3 , and P0 4 . The low intensity of the burns did not significantly reduce soil water
iron, as is known to occur in hot burns (Stark 1977). Logging temporarily increased
soil water levels of F, Mg, Mn, N03, Na, and Zn. This is the result of the rapid winter
decay of a heavy green needle loading on the surface of the soil following logging.
Slash removal often did not reduce soil water ion concentrations because wood to 3 inches
(7.6 ern) was mainly removed, leaving behind large quantities of fine branches and needles.
The needles began decaying under the snow during the first winter, whereas the recently
cut heavy wood would release very few nutrients during the first winter.
Direct analysis of soil water is a more reliable indicator of short-term changes
in soil water chemistry, than are artificial soil extraction procedures.
In this ecosystem, total nutrient losses beyond the reach of roots were insignificant. The data suggest that minimal surface disturbance by skyline logging does not
cause excessive nutrient losses from the ecosystem. Although clearcutting influenced
soil water quality more than did shelterwood cutting, neither produced serious nutrient
losses. Burning increased soil water ion loads for a year, but the generally lowintensity burns prevented massive nutrient losses below the root zone. A full evaluation of nutrient losses from harvest and slash treatment requires measurements of the
nutrients removed in harvested wood and bark. These measurements are being reported
separately. The study demonstrates that logging and slash disposal as practiced here
are not damaging in terms of excessive soil nutrient losses beyond the root zone or
through overland flow into streams. Different results can be expected with different,
more erosive soils or logging methods that disturb the surface soil.
Abbott Creek
Abbott Creek runs underground for 0.12 mile (0.2 krn) and may dry up or disappear
in late summer. Samples taken from above and below the treated areas actually showed
a reduction in ion content, which is probably the result of 0.12 mile (0.2 km) underground transit. For this area, a watershed-type study was impractical. For a week
postburn, there was a slightly elevated level of ions in the creek, but statistically
not significant. Other studies involving cutting have shown considerable export of
nitrogen and other ions in stream water on watersheds with impermeable bedrock (Bormann
and others 1968).
INFLUENCE OF WOOD REMOVAL ON NUTRIENT CYCLING
Methods
To estimate how much of the biologically essential nutrients were being removed
from the site as a result of harvest, it was necessary to analyze wood and bark in their
naturally occurring proportions. All three silvicultural treatments were studied in
duplicate, and all utilization treatments except the heavy utilization treatment, which
included wood, bark, needles, and branches.
During harvest, wood and attached bark were collected from eight tree species,
living and dead, using increment borings and cross-sections. Nutrient removal was based
on the weight of bole wood removed. Volumes of wood removed per plot by species were
converted to weight (kg) of wood and bark removed.
16
All plant samples were dried at 149°F (65°C), finely ground to under 0.069 inch
(1 mm) and ashed in a muffle furnace at 977°F (525°±5°C) for 2 hours (Jackson 1958).
The elements Ca, Cu, Fe, K, Mg, ~~' Na, and Zn were analyzed by atomic absorption
spectrophotometry (Techtron 1974) and phosphate was measured by colorimetry (Jackson
1958). Total nitrogen was measured by the modified microKjeldahl procedure (Hesse 1972).
Over a period of three summers, duplicate soil extractions were made from the study
site on 600 samples each year, using 0.002N H2 S04 extractant and measuring the same elements as were analyzed in plant samples. Two hundred soil and rock samples were also
digested in HF-HCL0 4 to determine total elemental content of the root zone. The percentage of rocks and the depth of the root zone were determined in the field. In addition, 500-800 soil water samples were extracted each year using soil moisture probes
under tension, and were analyzed on the atomic absorption spectrophotometer with bulk
precipitation, throughfall, and stream water for the same elements. An Orion specific
+
ion analyzer was used for H , F , N0 3 N, and a colorimeter for P0 4 P by the most sensitive method for water (Farber 1960). These data constitute more than 300,000 measurements and are reported briefly in the first portion of this paper. They were used in
calculating the actual amount of each element removed from the ecosystem during harvest.
Results and Discussion
The site index for western larch is 65 (SI 50-70, 50 years; Ray Shearer, personal
communication, Forestry Sciences Laboratory, Missoula, Mont.) for the area and is reasonably uniform so that greater diameter usually means greater age. Wood of the same
species varied considerably in elemental content with age and diameter (table 4). Sampling from increment borings made it possible to analyze the proper proportion of wood
to bark for each diameter class. Elemental differences with size were the result of
thicker bark with age, changing wood/bark ratios, and progressive storage of waste products in older wood. Often wood in the 6-12 inch (15.2-30.5 ern) size class was lower in
elemental content than either the younger or older wood although there were exceptions
(table 4).
Generally, western white pine (Pinus monticola Dougl.) and western hemlock (Tsuga
heterophylla [Raf.] Sarg.) were low in calcium and copper compared to the other species
(table 4). Harvest of alpine fir (Abies lasiocarpa [Hook.] Nutt.) and Engelmann spruce
(Picea engelmannii Parry) wood and bark would remove the most calcium from the site
(table 4). Alpine fir, Douglas-fir, western hemlock, and western larch were the highest
in phosphorus. Engelmann spruce and western larch had relatively high levels of zinc
while western redcedar (Thuja plicata Donn.) wood plus bark was low in zinc. Harvesting
the wood of alpine fir and Douglas-fir would remove more nitrogen than would harvest of
other tree species. The most magnesium would be lost in the wood and bark of Douglasfir, western hemlock, and western white pine. Alpine fir, Douglas-fir, and Engelmann
spruce wood and bark were high in potassium (table 4). Potassium is usually low in
supply in western forest soils.
Obviously, harvesting practices cannot be built around those species that are
lowest in total elements removed with wood and bark, but a knowledge of relative nutrient losses by species can be important if the site to be harvested is extremely low in
the available form of one biologically essential element and the species to be removed
contains high levels of that element. Figure 3 shows the lower group selection (left)
clearcut (right) after logging.
Table 5 shows how much merchantable wood was removed from each silvicultural prescription and treatment. The amount removed is a function of the density and size of
the original stocking, and the intensity of utilization. The data represent a summation of volumes of all species present. Nutrient removal was based on the species
components of the total volumes. Shelterwood cuttings removed from 576 to 2,950 ft 3 /
acre, while group selection cuts removed from 5,765 to 12,254 ft 3 /acre.
17
00
1-'
<15.2
<30.5
>30.5
<15.2
<30.5
>30.5
< 6
<12
>12
< 6
<12
>12
Douglas-fir
Engelmann spruce
<15.2
<30.5
>30.5
<15.2
<30.5
<15.2
<30.5
< 6
<12
>12
< 6
<12
< 6
<12
Western white pine
Westerm hemlock
Western redcedar
diameter.
2 The
:
:
:
:
:
Fe :
K
:
:
1450
1034
913
783
955
765
848
1415
1071
1186
1000
1800
777
2100
3330
2900
2100
1125
1586
3406
3138
2467
7.0
5.2
6.6
6.3
6.4
5.9
5.8
8.7
9.5
9.0
8.7
8.9
5.8
8.8
9.0
10.9
9.6
7.7
9.3
9.1
10.6
9.2
31
35
29
36
33
37
26
39
56
33
11
24
31
179
36
24
29
17
26
72
28
39
257
223
403
423
201
270
230
699
374
392
345
330
253
878
1000
933
1022
305
517
1003
738
1126
+
5
4
190
153
42
31
67
167
71
81
120
140
75
81
77
115
93
43
71
152
111
123
N
:
:
:
Na :
p
:
:
Zn
784
898
700
707
602
607
553
1176
607
476
700
560
630
805
1009
653
1208
884
1374
1089
1610
2602
30
26
33
36
30
25
33
24
17
23
19
20
28
20
22
30
21
18
24
29
25
20
132
218
765
541
155
149
164
673
486
350
288
152
310
323
473
454
716
657
669
527
659
406
2.4
3.0
6.0
5.6
11.5
7.4
8.3
12.7
42.4
9.6
11.0
11.5
11.6
21.4
23.9
11.3
14.5
9.3
12.1
12.1
8.4
10.2
- - - - - - - - - - - - -
:
Ash
0.6
0.6
0.5
0.5
0.2
0.2
0.2
0.8
0.6
0.2
0.5
0.7
0.5
1.2
0.8
0.9
0.5
0.6
0.5
1.5
1.0
0.9
Percent
--
:
bark from 15.2 to 30.5 em (6-12 inches) in
128
91
232
174
240
170
212
180
64
132
22
22
185
137
163
126
234
394
91
227
16
27
~g/g
:
Element
Mg : Mn :
- - - - - - - - - - - - - -
Cu :
Ca :
Appendix A for scientific names.
size category <30.5 em (12 inches) covers samples from wood
<15.2
<30.5
>30.5
< 6
<12
>12
Western larch
1See
<15.2
<30.5
>30.5
< 6
<12
>12
Lodgepole pine
2 <30.5
·<15. 2
em
>30.5
Inches
< 6
<12
>12
:
D.b.h. class
Alpine fir 1
Species
Table 4. --Average elemental content of bark plus wood for live cormnercial wood from the Coram Exper1:mental Forest
Figure 3.--Lower group selection cut (left) and clearcut block (right) at the Coram
Experimental Forest after logging. A portion of the upper clearcut shows in the
upper right hand corner.
Table 5.--Total volume of wood 3-inch diameter and larger (7.6 em) apparently removed
in harvest 1
Treatment
2
Block
-
Shelterwood 1
Group selection 1
Clearcut 1
Shelterwood 2
Group selection 2
Clearcut 2
1
- - - -
4
3
- - - - Cubic feet - - -
1,248
5,765
4,323
576
12,254
4,519
2,876
7,586
6,426
2,773
6,214
6,387
1,614
8,607
5,895
1,013
9,009
4,035
2,950
7,655
4,962
2,570
6,241
3,533
1 Derived
by subtracting postharvest volume from preharvest volume, Benson and
Schleiter (review draft). See tabulation for treatment definitions.
The data provide a rough estimate of the amount of nutrients likely to be removed
with the three silvicultural prescriptions on these habitat types for mature forest.
Elemental losses from harvest can be evaluated in terms of the levels of available
elements in the soil, or the available plus potentially available elements in soil, or
the total elemental content of the ecosystem (soil+ plants+ animals+ precipitation).
Ideally, harvest losses should be evaluated against total ecosystem nutrient levels
(available and stored, separately). This is a difficult comparison because of the
problem of measuring animal biomass and elemental content on a unit area.
Data presented cover losses from logs only and do not reflect the losses from
intensive fiber utilization. The calculations of nutrient loss from harvest relative
to the total biologically essential elemental content to the limit of the root zone were
based on a meter square surface area to the depth of 19.6 inches (50 em), with a bulk
density of 1.92 g/cm 3 (includes coarse rock fragments, not a typical andic soil).
19
The soils have moderate reserves of total calcium (5,240 g/0.5 m3 root zone) but high
levels of total iron (29,731 g/0.5 m3 ), and high levels of potassium (19,573 g/0.5 m3 ,
table 6). Calcium and magnesium are the macroelements that are in shortest su~ply and
most vulnerable to ultimate depletion. Phosphorus is quite low (1,621 g/0.5 m). The
sampling sites did not include the calcareous material that underlies part of the Coram
Experimental Forest.
In terms of available elements, calcium is relatively abundant (857 g/0.5 m3 ),
indicating that it is being readily released from the parent material and could easily
be lost (table 6). Magnesium is available in low amounts (89 g/0.5 m3 ) relative to
calcium. Copper losses were high on a percentage basis because total soil copper is
low. Low amounts of potassium (171 g/0.5 m3 ) and iron (30 g/0.5 m3 ) are available in
the root zone. Phosphate (as P04-P) is available in large amounts relative to its total
content in the soil as P (table 6) .
Table 7 shows the amount of each element removed from the site through harvest,
divided by the total elemental content (available + potentially available) of the soil
expressed as a percent. The four treatments are discussed under the Introduction, but
data are relative to log removal only (merchantable and unmerchantable dead and alive).
These results show that clearcutting and group selection removed the most cations relative to the total potentially available cations in the soil (0.18-0.21 percent, table 7).
Clearcutting removed total cations amounting to from 0.05 percent to 0.18 percent of
all the measured essential cations stored in the soil. Shelterwood cutting removed
from 0.03 percent to 0.17 percent of the total soil cation~ (eight of biological importance). In terms of the total cation content of the soil, clearcutting of the type of
CCI or group selection cuts of the type on GS2 removed the most cations relative to
the soil total content. In absolute terms, neither of these logging methods produced
serious nutrient losses in wood plus bark if viewed as a single treatment on a 70- to
100-year rotation.
The largest cation losses for CC2 and GS2 occurred in treatment 1 where trees were
removed down to 3 inches d.b.h. (7.6 em) and the understory was cut. Treatment 2 produced the largest total cation losses for SWl and GSl. On clearcut 1, treatment 4
removed the most total cations (relative to total root zone cations). More total biomass was removed in treatment 3 than in 1. Treatment 3 included the removal of needles
and branches, but no data are available at this time on the weights of slash removed
(only bole wood), so that nutrient loss from slash removal is not reflected in the data.
The actual losses of ions from any one site varied according to the intensity of harvest,
the original species present, and stocking, so that similar treatments did not show the
same cation losses.
.·
Harvesting wood + bark produced low percentage losses of Fe, K, Mg, Na, and Zn
(table 7). These elements were either low in the materials harvested or high in the
soil in total content. Calcium losses were only 0.2 to 1.7 percent of the total calcium, so that little harm was done to this relatively scarce ion (total) from harvest.
Magnesium losses were even lower (0.02 to 0.23 percent) than those for calcium. Even
the phosphorus removed in wood was low (0.2 to 1.2 percent of total soil P) and of no
serious immediate concern. On the basis of total elemental content, none of the logging
methods or intensities used produced significant losses of essential cations from the
total ion reserve in the soil through removal of wood or bark. A 0.2 percent loss of
the essential cations means that 70-100 year rotations could continue for 28,000 to
40,000 years before most ions would be depleted from the soil. The highest cation loss
was for total P0 4 . If 1.2 percent of the total P0 4 were lost each 100 years, it would
take 8,300 years for depletion of P0 4 from the soil and rocks. Deficiency conditions
would reduce growth before 8,300 years. Microerosion would also expose the roots to
freshly weathered soil during that time. Time spans in excess of 500 to 1,000 years
are not realistic to management because of the innate change in forest ecosystems.
Glaciation, volcanic action, speciation, climatic change, migration, invasion, and
other factors will all too soon change the forest that we are trying to manage now.
20
Table 6.--Total and available elemental content of a ~ide range of Coram soils, averaged to 50 em depth, and calculated as g/0.5 m3
Element
Parameter
N
Total
Total
p.g/g
g/0.5 m3
1,190
1,142
Available g/0.5 m3
Fe
Cu
Ca
K
Mg
Mn
p
Na
Zn
5,460
29
30,970
20,388
5,551
1,200
6,962
1,688
274
5,240
28
29,731
19,573
5,329
1,152
6,684
1,621
263
30
171
89
44
15
1,144
2.8
857
0.9
Table 7.--Percentage of total elements removed from a 1 m2 surface area in logs by a
single harvest ( clearcut~ selection cut~ or shelterwood) on the basis of
g/0.5 m3 feeder root zone~ relative to total root zone
Si1vicultural: Treatpractice
ment 1
Shelterwood 1
Group
selection 1
Clearcut 1
She1terwood 2
Group
selection 2
C1earcut 2
1 Treatments
Ca
Cu
Fe
Elemental content
K
Mg
Mn
N
Na :P0 4
Zn
2
4
1
3
1.2
.4
.9
.6
1.2 0.004 0.11 0.17 0.33 2.6 0.01 0. 76 0.19
. 5 .002 . 04 .14 .10 1.2 . 004 .43 .25
1.0 .006 • OS . 09 .17 2.4 . 02
.25 .19
. 7 .003 • OS . 07 .13 1.7 .006 .59 .12
2
4
1
3
1.1
.6
.5
.9
1.1
.8
.6
.9
.001
. 002
.002
. 003
2
4
1
3
.4
1.3
.4
.3
.5
2.0
.4
.3
2
4
1
3
.2
.4
.4
.3
2
4
1
3
2
4
1
3
.12
. 07
Percent
total
cations
removed
0.17
. 07
.12
.08
. 08
.15
.14
. 06
. 10
.23
.16
.11
.18
2.7
2.1
1.6
2.2
. 01 1. 20
.007 . 63
.006 .53
. 008 . 67
.20
.10
. 09
.12
.16
.09
.08
.12
.001
.004
. 001
.001
. 04
. 09
. 03
. 03
.12
.23
. 04
. 03
.10
.42
. 08
. 08
4.5
5.1
4.2
1.4
.004
. 02
.004
. 004
. 21
.57
.43
.36
.06
.26
. 08
.06
.18
• OS
.05
.3
.4
.4
.3
.001
.001
.001
. 001
. 02
. 03
. 03
. 03
. 02
. 03
. 04
. 03
• OS 1.2
. 08 1.3
. 08 4.2
.08 1.4
. 002
.003
.004
.004
.26
.38
.43
.36
• OS
. 06
.08
.03
.05
• OS
• OS
.05
1.2
.8
1.7
.7
1.2
.8
2.9
.7
.003
.002
.005
. 002
. 09
. 07
. 11
. 07
. 12
. 08
.13
. 08
.26
.16
.25
. 04
3.0
2.2
4.5
2.0
. 01
.007
. 92
.006
. 87
.71
. 95
.59
.20
.11
.18
.09
.16
. 11
. 21
.10
.9
.6
1.1
.6
.9
.7
.9
1.4
.002
.002
.003
. 002
. 09
. 07
. 09
. 06
. 09
. 07
. 09
.14
.16
.22
.13
2.3
1.9
2.6
1.6
.008
.007
.009
. 005
.50
.52
. 74
.42
.12
.10
.14
.07
.12
.09
.15
.08
• OS
• OS
described under Methods, least severe to most severe
21
.OS
2, 4, 1 ' 3.
When harvest losses are examined on the basis of the percentage of the available
soil cations removed, larger percentages of ions were taken from the site, representing from 1.9 to 13.9 percent of all the available cations in the root zone at one point
in time (table 8). Again, each site varied according to stocking and treatment. The
largest percentage losses were for zinc (14.8-91.7 percent of immediately available Zn).
Table B.--Representative percentage of available soil elements removed by clearcutting,
selective cutting, and shelterwood cutting
Treatment1
Block
Shelterwood 1
Ca : Cu : Fe :
Element
K : Mg :
~m
: Na :
P : Zn
: Percent
:available
cations
removed
1
3
8.6 13.5
3.1 5. 7
6.3 11.5
4.3 7.9
4.7 14.1 11.6
1.9 5.7 9.7
6.6 7.0 6.5
3.4 6.9 4.6
9.9
2.9
5.1
3.9
5. 7 1. 25
2.3 .71
8.3 .41
3.1 . 96
62. 7
80.1
62.6
40.3
9.5
4.0
6.4
4.6
Group selection 1
2
4
1
3
7.8 12.8
3.9 9.2
3.9 6.9
6.1 10.5
1.4 16.1 10.5
2.4 9.3 5.9
2.0 6.8 4.4
3.0 11.0 6.9
6.9
4.9
3.4
5.6
5. 3 1. 98
3.8 1.03
3.0 .88
4.3 1.10
64. 7
33.6
29.6
39.6
9.0
4.9
4.3
6.8
Clearcut l
2
4
2.7 5.3
9.1 23.5
12.2 17.3
5.8 13.9
1.2 5.2 3.2 2.9
4.7 10.5 15.8 12.8
3.9 27.4 11.2 9.2
2.8 9.8 8.8 7.5
2.1 . 34
7. 9 . 94
6. 8 2. 01
5.5 .58
19.1
84.3
91. 7
48.2
3.0
10.1
13.9
6.6
1.1
1.5
1.6
1.7
2
4
l
3
Shelterwood 2
2
4
1
3
Group selection 2
2
4
1
3
Clearcut 2
2
4
1
3
1Treatments
1.7
2. 5
2.6
2.3
2.9
4.1
4.5
3.6
2.6
3.9
4.1
3.7
1.6
2.4
2.5
2.3
1.6
2.4
2.6
2.5
1.2
1.7
1.9
1.9
15.3
20.7
24.7
14.8
1.9
2.8
2.9
2.6
8.3 14.2
5.4 8.9
li. 7 34. 2
5.2 8.0
4.0 11.4
2.5 8.2
5.9 13.4
2.3 7.8
8.2
5.6
9.3
5.3
7.9
4.9
5.6 1.43 65.4
3.8 1.16 35.9
9.2 1.57 59.0
3.3 .96 29.8
8.9
5.9
11.8
6.3 9.6
4.6 8.1
8.0 11.2
4.3 16.5
2.610.1
2.4 8.1
3.1 10.8
1.8 6.6
6.1
4.6
6.3
3.8
3.9 .82 38.4
3.4 .86 31.9
4.6 1.21 44.4
2.8 .68 23.2
6.9
5.2
8.3
4.6
7.7
1.1
4.4
4.9
6.5
3.9
.43
.63
.71
.59
5.5
described under Methods.
Only in the case of Zn is there a possible problem with future zinc deficiency because
weathering might not be able to replace the needed Zn fast enough to accommodate new
growth. This deficiency will probably not occur because burning released added zinc on
some treatments, and it will be 20 years or more before the young regeneration is large
enough to make severe demands on the soil for zinc. Available nutrients were not actually removed at one time from the soil through harvest, but gradually over a long time
(70+ years).
Zinc removal to close to 100 percent does not mean that after harvest
there was almost no available Zn left in the soil, but the amount of Zn removed in harvest is about what was available in the entire root zone at one point in time. The
roots are never able to extract all of the available zinc present in any soil at one
time. Some zinc is always present in excess of what is actually being used by roots.
22
Most other elements showed low percentage losses relative to the available soil
cations, normally under 10-15 percent. Calcium losses ranged from 2.3 to 12.2 percent
of available Ca, and magnesium from 1.6 to 15.8 percent. Potassium losses were 2.6 to
27.4 percent of available K. Phosphate losses were low (0.3-2.0 percent of available
P0 4 ). Shelterwood showed markedly lower percentage losses of cations when compared to
all other blocks. The reason for this is unknown. These data indicate that the system
has lost low percentages of the available soil cation and anion pool, and that these
ions will not be available after harvest to be recycled through decomposition. The
rep:icate harvest plots were from soils that were somewhat chemically different.
Realistically, the levels of elements taken from the logged sites should be corrected for the elemental input from precipitation (table 9). When corrections are made
for precipitation additions as me/m 2 (table 10) the importance of harvest losses is
further reduced. This is particularly true if we assume a 70-100 year rotation, and
multiply the average additions by 100. Over 100 years, approximately 37 g/m 2 of Ca,
1.3 g of Cu, 5.7 g of Fe, 45 g of K, 31 g of Mg, 2 g of Mn, 120 g of N0 3 , 300 g of Na,
15 g of P0 4 , and 3 g of Zn, or about 425 g of cations and 140 g of anions would be
added to each meter square of the ecosystem. These data apply to only this area where
there is enrichment of the atmosphere from an industrial stack (table 9). The harvest
losses must be balanced against other liquid and solid elemental losses (smoke, dust,
runoff) over the 100 years. At this time, we cannot make this type of prediction, but
ultimately this should be possible. This area does not have a permanent stream so that
elemental losses to running water could not be measured. Where logging triggers erosion,
nutrient losses would be far greater than reported here where erosion was nonexistent.
Harvest data corrected for elemental additions from rainwater show a net gain over
100 years in copper, iron, potassium, magnesium, sodium, nitrogen, phosphate, and zinc
(table 9). This means that for most elements studied and for a 100-year rotation, precipitation would restore all but the calcium and manganese removed by harvest in wood
and bark. In most cases this holds for a 70-year rotation as well. Calcium and manganese harvest losses would, by calculation, be replaced in 100 years of precipitation
for SW2, which had the lowest nutrient losses in the wood and bark harvested. This
ecosystem shows high sodium replacement, which may be related to stack emissions from
a nearby aluminum plant 11 miles (17.7 km) southwest at Columbia Falls. Clearcutting
produced the greatest nitrogen losses, but these would be more than adequately replaced
by precipitation and fixation. These results assume no drastic changes in precipitation
amounts over 100 years (for calculation purposes).
Only a few studies have dealt with nutrient removal through harvest. Weaver and
Porcella (in press) reported that nutrient losses from whole tree harvest reduced ecosystem nitrogen by about 3x, phosphorus by 6x, potassium by 4x, and calcium by 3x compared to conventional log removal.
Long and Turner (1975) have described the aboveground biomass of understory and
overstory Douglas-fir stands by age class. Odegard (1974) discussed nutrient and biomass relationships following clearcutting of lodgepole pine forests. Ovington and others
(1973) described the biomass and nutrient capital of old-growth Douglas-fir stands. Few
studies have included information taken directly from harvest. Carlisle (1967) showed
that for oak forests nutrient input from precipitation in 12 years replaced harvest
losses for 60- or 120-year rotations.
Weetman and Webber (1971) concluded that full-tree logging would not damage the
soil for the next crop of spruce, with the possible exception of calcium deficiencies.
They felt that sites of marginal fertility should not be subjected to full-tree logging
unless fertilizer is applied to the soil. This view was also expressed by Tamm (1969).
Other data showed large inputs of nutrients from dust and precipitation. Wilde and
others (1972) showed that red pine can grow on soils which by chemical analysis show
low fertility. These and other data point to a growing belief that forest trees can
extract more nutrients from soil than are reflected in chemical analysis (Bowen 1972).
23
Table 9.--Average annual and 100-year expanded additions of ions to the forest ecosystem
from bulk precipitation
Time span
Average
annual
Ion
Time span
Average
annual
Ion
100
years
..
- Grams/square meter -
- Grams/square meter 0.37
.013
.057
. 055
.453
.306
.019
Ca
Cu
Fe
F
K
Mg
Mn
100
years
37.0
1.3
5.7
5.5
45.3
30.6
1.9
1. 20
3.0
.149
.031
N03
Na
P0 4
Zn
Cations
Anions
120.0
300.0
14.9
3. 1
425.0
140.0
Table 10. --Levels of elements removed in wood and bark .from the Coram Experimental Forest~
corrected for estimated 100-year elemental additions from bulk precipitation
Treatment 2
Ca : Cu
Element
Na
Mg : Mn : N
- - - - - - g/m 2 /100 years Fe : K
p
Zn
Shelterwood 1
2
4
1
3
26
+14
9
+6
+0.9
+1. 2
+1. 0
+1. 1
+4.5
+5.2
+4.0
+4.8
+25
+37
+35
+35
+22
+23
+26
+27
1.9 +91.3
+ .8 +106.8
.02 +93.8
+ .4 +101.2
+299
+300
+299
+300
+2.6
+7.9
+10.8
+5.4
+2.6
+2.5
+2.6
+2.8
Clearcut 1
2
4
1
3
+18
30
53
5
+1. 2
+ .7
+ .9
+ .9
+5.4 +38
+4.5 +28
+4.7 +5
+4.9 +31
+28
+18
+22
+24
+ .8
2.9
1.6
.9
+70.2
+62.9
+32.9
+72.9
+300
+299
+299
+299
+11. 5
+5.7
4.9
+9. 2
+2.9
+2.4
+2.4
+2.7
Shelterwood 2
2
4
1
3
+24
+18
+18
+20
+1. 2
+ .3
+1. 2
+ .4
+5.4
+5.3
+5.3
+5.3
+41
+39
+39
+39
+29
+29
+29
+29
+1. 3 +107.2
+1. 0 +105.8
+ .9 +73.3
+ .9 +104.2
+300
+300
+300
+300
+10.6
+8.7
+7.9
+9.1
+3.0
+2.9
+2.9
+3.0
Clearcut 2
2
4
1
3
10
+3
22
+5
+1. 1
+1. 1
+1. 0
+ .9
+5.0
+5.1
+4.9
+5.2
+29
+32
+28
+34
+29
+29
+28
+29
. 2 +94.4
+ . 01 +98.9
. 6 +91.0
+ .4 +102.2
+299
+300
+299
+300
+6.8
+6.4
+3.0
+8.2
+2.8
+2.8
+2.7
+2.9
1No precipitation data are available for the group selection plots.
2 Treatments described under Methods.
+ = additions of elements above levels removed on a 100-year rotation. Other
figures represent amount by which precipitation fails to replace harvest losses.
Cole and others (1967) discuss the problem of determining accurately the quantity of
nutrients released by geochemical weathering.
The nitrogen content of spruce slash was reported as 167 to 387 kg/ha. This constitutes a major source of the potentially mineralized organic N (Weetman and Webber
1971). This same study concluded that adequate nitrogen would be left in the litter
and humus layer to support the next forest (initially), even with tree-length logging.
Gessel and Cole (1965) found that the removal of vegetation resulted in a 6 percent
loss of K below the root zone.
24
CONCLUSIONS
On the relatively fertile soils at Coram, none of the harvest intensities used
(clearcut, shelterwood, or group selection) with varying degrees of site preparation
removed nutrients in amounts that should affect growth for thousands of years. Nutrient
losses did vary by treatment, but not in amounts significant to management. One unknown
in evaluating the impact of land use on nutrient losses is our inability to determine
accurately how fast rock weathers with depth. The weathering rate is the key interest
rate at which nutrients are made soluble and available to plants. Leaching losses
represent the permanent expenditure of biologically essential nutrients from the system.
The amounts of nutrients removed in the harvest of logs, even with clearcutting, will
normally be replaced by bulk precipitation in from 70 to 100 years. This should hold
true when the harvested species are alpine fir, Douglas-fir, western larch, western
white pine, western redcedar, lodgepole pine, Engelmann spruce, and western hemlock on
similar soils. Unfortunately, we cannot put long-term dollar values on the nutrients
lost.
Skyline logging did not produce serious erosion or soil losses. This is surpr1s1ng
in view of the steep terrain (45 percent) and the fire lines that had to be built.
Certainly these results could not be extrapolated to any area of similar topography.
The combination of a productive surface soil with abundant organic matter and a tremendously dense herb and shrub layer prevented erosion. The surface disturbance from this
method of logging was minimal, and the vigorous regrowth of vegetation held both nutrients and soil in place.
This vigorous regrowth probably also explains the low levels of solution nutrient
loss from the system. The ephemeral stream, Abbott Creek, was essentially unaltered
chemically by the extensive logging of the watershed that feeds it. Part of this is
the result of the underground transit of this stream, and part results from rapid
regrowth of the vegetation preventing excessive nutrient losses from the slopes.
Clearcutting exported more nutrients below the root zone than did any of the other
treatments. These nutrient losses were low and only slightly elevated above those of
the controls. They were also relatively short-lived. Logging temporarily increased
the levels ofF, Mg, Mn, N0 3 , Na, and Zn in the soil water. These nutrients appear to
have come from rapid winter decay of needles under a deep, dense snowpack. Soil water
appears to be the best and most dependable indicator of the levels of available nutrients in soil.
Burning increased soil water ion loads for a year, but the burns were of low intensity and the ion additions were all quite low. Data on the nutrient content of the
vegetation suggests that the herbs and shrubs were taking up large quantities of the
nutrients released from burning. This study demonstrated that skyline logging as practiced on these slopes with this soil did not result in massive solution or erosion
nutrient losses. The harvest losses in wood and bark were also relatively low and- will
be replaced by precipitation if not by weathering during the next rotation.
25
'·.·· .:
APPLICATIONS
One important use of these results is to compare other areas to be logged to Coram.
Appendix B shows details of the soil characteristics of the area, and Appendix A provides
an idea of species diversity. Appendix C shows the range of soil chemistry for the
general study area. Areas that vary considerably from this area in terms of soil chemistry, soil physical properties, slope, aspect, or vegetation should be looked at carefully before extrapolating these results. Quite different results could be expected on
steeper slopes, for example. An erosive soil, such as some silt learns, fine sands, or
some loams or silts would produce potentially higher nutrient losses than occurred at
Coram. Clay soils may cause accelerated surface losses. Also, older soils more highly
weathered may lose fertility faster if exposed to this type of nutrient loss, even at
low levels. Fertile soils will probably suffer less than very poor soils. Talus slopes
with low total soil depth, little weathered, and with extremely low levels of available
nutrients may not be able to withstand this type of logging treatment without irreparable
nutrient losses. A different system of removing logs will surely produce different
degrees of surface disturbance and more or less nutrient loss as well as differences in
erosion. Hotter fires would create a greater chance of nutrient losses and could alter
the conclusions reached here. Even a south slope with sparse vegetation and different
species will respond in an altered manner to logging, and would be expected to lose
more nutrient in years of heavy precipitation. A permanent, aboveground stream will
react differently to disturbance on the slope. Infiltration is also a big factor in
nutrient loss. Soils that characteristically freeze deeply in winter or that have heavy
clay surfaces may well produce overland nutrient losses not encountered at Coram. Even
the Coram slopes may alter their nutrient losses in a year of exceptionally heavy precipitation, or very light or heavy snowpack.
Different land use history may influence the response of an area to logging.
Heavily compacted soils, or flat ground will release nutrients differently than occurred
at Coram. Also important is stoniness or rockiness. The heavy stone content of Coram
soils aided infiltration and percolation of water and made this soil more able to store
the modest amounts of nutrients released from logging and burning. Certainly a change
in vegetation type would alter the ability of a site to absorb and retain nutrients.
Vegetation which sprouts and regrows rapidly should be best suited to logging disturbance, but not necessarily to regeneration of trees. The intensity and method of site
preparation will alter a site's ability to retain nutrients. High water tables and
moist sites will lose nutrients readily. Logging must be evaluated in terms of the
holocoenotic environment, the whole that is influenced in many ways by all of its parts.
Every area to be logged is a bit different. The greater the difference from the
Coram study site, the greater the chances of more or less nutrient losses. Harvest will
probably not remove significant levels of nutrients from any but the poorest very old or
very young soils. Solution losses are highly dependent on the depth of soil, amount of
precipitation, amounts of carbonates and bicarbonates in the soil solution, soil texture,
and clay and organic content, and the cation and anion exchange capacities.
We are not yet ready to write prediction equations for any forest
ent retention for any treatment, but we do have a "feel" for the types
suffer most from logging or fire. Current logging and burning studies
clay soils will add to this knowledge. We might not always be able to
ferent conditions need to be from those at Coram to be significant.
in terms of nutriof areas that will
on predominantly
say how much dif-
More work needs to be done on nutrient removal associated with heavy utilization.
We need to answer the question, "How much fiber can be removed from a site before the
ability of the soil to grow the next rotation is impaired?" We are working on this.
Because the Coram study showed no serious nutrient losses, we cannot assume that any
forest or soil will respond the same way. We are, however, in a good position to estimate the magnitude of losses on other sites.
26
PUBLICATIONS CITED
Artley, Donald K., Raymond C. Shearer, and Robert W. Steele.
1978. Effects of burning moist fuels on seedbed preparation in cutover western larch
forests. USDA For. Serv. Res. Pap. INT-211, 14 p. Intermt. For. and Range Exp.
Stn., Ogden, Utah.
Bormann, F. H., G. E. Likens, D. W. Fisher, and R. S. Pierce.
1968. Nutrient loss accelerated by clear-cutting of a forest ecosystem. Science
159(3817) :882-884.
Bowen, C. W.
1972. Progressive acid dissolution as a technique for determining the potassium supply of forest soils. M.S. Thesis, Univ. Mont., Missoula.
Carlisle, A., and others (other authors unknown).
1967. The nutrient content of rainfall and its role in the forest nutrient cycle.
Proc. XIV IUFRO Congr. Munchen Pt. II, Sec. 21:1450158. S. P. Gessel and S. F.
Dice, ed.
Cole, D. W, S. P. Gessel, and S. F. ·Dice.
1967. Distribution and cycling of nitrogen, phosphorus, potassium and calcium in a
second-growth Douglas-fir ecosystem. In Symp. on primary productivity and mineral
cycling in natural ecosystems, p. 198-232. Univ. Maine Press.
Eron, Zati.
1977. Heat effects on forest soil physical properties and subsequent seedling growth.
(Microfilm) Ph.D. Dissert., Univ. Mont., Missoula, 184 p.
Farber, L., ed.
1960. Standard methods for the examination of water and waste water. Am. Publ. Health
Assoc. and Am. Water Works Assoc., New York, N.Y.
Fredriksen, R. L.
1971. Comparative chemical water quality--natural and disturbed streams following
logging and slash burning. In Forest and land uses and stream environment, p.
125-137. Oreg. State Univ., Corvallis.
Fredriksen, R. L., D. G. Moore, and L. A. Norris.
1975. The impact of timber harvest, fertilization and herbicide treatment on stream
water quality in western Oregon and Washington. In Forest soils and forest land
management. Proc., 4th North Am. For. Soils Conf., Quebec, 1973, p. 283-313.
B. Bernier and C. H. Winget, ed. Laval Univ. Press, Quebec.
Gessel, S. P., and D. W. Cole.
1965. Influence of removal of forest cover on movement of water and associated elements through soil. J. Am. Water Works Assoc. 57:1301-1310.
Hesse, P. R.
1972. A textbook of soil chemical analysis. 520 p. Chemical Publishing Co., New
York.
Jackson, M. L.
1958. Soil chemical analysis. 498 p. Prentice-Hall, Englewood Cliffs, N.J.
Klages, M. G., R. C. McConnell, and G. A. Nielsen.
1976. Soils of the Coram Experimental Forest. Mont. Agric. Exp. Stn. Res. Rep. 91,
43 p.
Likens, G. E., F. H. Bormann, N. M. Johnson, and R. S. Pierce.
1967. The calcium, magnesium, potassium, and sodium budgets for a small forested
ecosystem. Ecology 49(5) :772-785.
Long, J., and J. Turner.
1975. Aboveground of overstory and understory in an age sequence of four Douglasfir stands. J. Appl. Ecol. 12:179-188.
Moore, D. G.
1974. Impact of forest fertilization on water quality in the Douglas-fir region--a
summary of monitoring studies. Natl. Conv. Soc. Am. For. Proc., p. 209-219.
27
Odegard, G.
1974. Nutrient and biomass distribution following clearcutting in a lodgepole pine
forest ecosystem. Ph.D. Dissert., Colo. State Univ., Fort Collins, 182 p.
Ovington, W., D. Lavender, and R. Hermann.
1973. Estimation of biomass and-nutrient capital in stands of old growth Douglas-fir.
In IUFRO biomass studies. H. Young, ed. Coli. Life Sci. and Agric., Univ.
Maine, Orono, 532 p.
Pfister, Robert D., Bernard L. Kovalchik, Steven F. Arno, and others.
1977. Forest habitat types of Montana. USDA For. Serv. Gen. Tech. Rep. INT-34,
174 p. Intermt. For. and Range Exp. Stn., Ogden, Utah.
Stark, N.
1977. Fire and nutrient cycling in a larch/Douglas-fir forest. Ecology 58:16-30.
Stark, N.
1978. Man, tropical forests, and the biological life of a soil. Biotropica 10(1):
1-10.
Tamm, C. 0.
1969. Site damages by thinning due to removal of organic matter and plant nutrients.
In Thinning and mechanization. Proc. IUFRO Manage., Sweden, 1975-1977.
Techtron, Ltd.
1974. Analytical methods for flame spectroscopy. Varian-Techtron PTY. Ltd.
Melbourne, Australia; Victoria.
Tiedemann, A. R.
1974. Stream chemistry following a forest fire and urea fertilization in north
central Washington. USDA For. Serv. Res. Pap. PNW-203, 20 p. Pac. Northwest
For. and Range Exp. Stn., Portland, Oreg.
Weaver, T., and F. Porcella.
In press. Biomass of fifty conifer forests and nutrient exports associated with their
harvest. Great Basin Naturalist.
Weetman, G. F., and B. Webber.
1971. The influence of wood harvesting on the nutrient status of two spruce stands.
Woodland Rep. WR/33, 26 p. Pulp and Paper Res. Inst. of Canada, Montreal.
Wilde, S. A., J. G. Iyer, and G. K. Voigt
1972. Soil and plant analysis for tree culture. 209 p. Oxford Publ. House, New
Delhi.
28
APPENDIX A
Plant Species Found on Coram Forest
29
0
(,N
Abies lasiocarpa/Clintonia uniflora h.t., Xerophyllum
tenax phase
Abies lasiocarpa/Clintonia uniflora h.t., Menziesia
ferruginea phase
ABLA/CLUN h.t.-XETE phase 2
ABLA/CLUN h.t.-MEFE phase
A/C-X-P
A/C-M
lJack Schmidt and Robert Pfister, Intermountain Forest and Range Experiment Station, Forestry Sciences Laboratory,
Missoula, Montana.
2Physocarpus malvaceus well represented in undergrowth community.
Abies lasiocarpa/Clintonia uniflora h.t., Aralia
nudicaulis phase
Abies lasiocarpa/Clintonia unij7ora h.t., Clintonia
uniflora phase
ABLA/CLUN h.t.-CLUN phase 2
A/C-C
ABLA/CLUN h.t.-ARNU phase
Abies lasiocarpa/Oplopanax horridum h.t.
ABLA/OPHO h.t.
A/0
A/C-A
Tsuga heterophylla/Clintonia uniflora h.t., Aralia
nudicaulis phase
TSHE/CLUN h.t.-ARNU phase
H/C-A
Scientific name
Pseudotsuga menziesii/Physocarpus malvaceus h.t.,
Physocarpus malvaceus phase
1977 abbreviation
PSME/PHMA h.t.-PHMA phase
:
:
0/P-P
1974 map
Table 11.--Habitat type and phase codes~ utilization study~ Coram Experimental Forest 1
Plant Species Found on Coram Forest*
Osmorhiza chilensis
Pachistima myrsinites
Pedicularis bracteosa
Pedicularis contorta
Pedicularis racemosa
Physocarpus malvaceus
Picea engelmannii
Pinus mont·ico la
Pseudotsuga menziesii
Pyrola asarifolia
Pyrola secunda
Ribes lacustre
Ribes viscossissimum
Rosa acicularis
Rosa gymnocarpa
Rubus parvifl.orus
Salix scouleriana
Sorbus scopu l1:na
Smilacina racemosa
Smilacina stellata
Spirea betulifolia
Symphoricarpos albus
Taxus brevifolia
Tiarella unifoliata
Trillium ovatum
Tsuga heterophylla
Vaccinium membranaceum
Vaccinium myPtillus
Viola adunca
Viola orbiculata
Xerophyllum tenax
Anaphalis margaPitacea
Apocynum androsaemifolium
Betula papyrifera
Calochortus nuttallii
Ceanothus sanguineus
Comandra umbellata
Cornus stolonifera
Habenaria dilitata
Polystichum munitum
Pteridium aquilinum
Senecio pseudaureus
Senecio triangularis
Shepherdia canadensis
Taraxacum officinale
Abies lasiocarpa
Acer glabrwn
Actea rubra
Adenocaulon bicolor
Alnus sinuata
Amelanchier alnifolia
Antennaria spp.
Aralia nudicaulis
Arnica cordifolia
Arnica latifolia
Aster conspicuus
Aster laevis
Athyrium filix-femina
Berberis repens
Bromus vulgaris
Calamagrostis canadensis
Calamagrostis rubescens
Carex concinoides
Carex geyeri
Carex rossii
Chimaphila umbellata
Cirsium vulgare
Clematis columbiana
Clintonia uniflora
Cornus canadensis
Disporum hookerii
Disporum trachycarpum
Dracocephalum parviflorum
Elymus glacus
Epilobium angustifolium
Epilobium watsonii
Equisetum spp.
Festuca occidentalis
Fragaria vesca
Galium triflorum
Gentiana amarella
GePanhifn bicknellii
Goodyera oblongifolia
GumnocaPvium dryopteris
Hieracium albiflorum
Larix occidentalis
Linnaea borealis
Lonicera utahensis
Melica subulata
Menziesia ferruginea
Oryzopsis asperifolia
*U.S. Forest Service list.
31
APPENDIXB
Soil Characteristics, Coram Forest
33
(.N
~
3.0-0.0
0.0-1.5
02
A2
33.5
1.5
3.0
4.0
Thickness :
--
--
10 yr
6/3
4/4
silt
loam
silt
loam
--
--
10 yr
4/2
6/1
--
--
very
friable
very
friable
--
--
fine
many
fine
common
fine
common
fine
few
:
clear
smooth
clear
smooth
clear
smooth
clear
smooth
Boundary
Organic matter upper 5 ern: 11.8%-15.6%
Hydraulic conductivity: 8.2-11.3 crn/h
Water holding capacity: 5 ern, 22%; B , 11%
2
Infiltration rate: 4 in (10.2 crn)/h
moderate
fine
crumbly
weak
fine
crumbly
--
--
Field
Color
: texture : Structure :Consistency : Roots
Dry :Moist: analysis:
: (moist)
Date: August 12, 1976
Soil type: gravelly silt-loam
Soil series: Sherlock (Klages and others 1976)
Soil subgroup: andeptic cryobonalf (Klages and
others 1976)
Family: loamy-skeletal, mixed (Klages and others 1976)
Elevation: . . . . 1800 rn
Slope: . . . . 5%-10%
Aspect: east
Parent material: glacial till (Klages and others 1976)
Habitat type: Tsuga heterophylla/Clintonia unifloria
(Pfister and others 1977)
1.5-35.0
7.0-3.0
82
:
- em -
01
Horizon : Depth
Table 12.--Soil description, Coram Forest, lower slope, adapted from Eron 19??
pH=6.3
%M=52.5
(14. 5 ern
depth)
Reaction
~
:
0.0-1.0
A2
39.0+
1.0
2.0
Coram
Forest~
upper
slope~
7/1
5/1
--
--
10 yr
10 yr
4/3
4/1
--
--
silt
loam
silt
loam
--
--
weak moderate
fine
crumbly
weak
fine
crumbly
--
--
firm
very
friable friable
--
--
fine medium
common many
fine
few
fine
few
fine
few
:
gradual
smooth clear
smooth
gradual
smooth clear
smooth
gradual
smooth clear
smooth
gradual
smooth clear
smooth
Boundary
adapted from Eron 1977
-:-Field
:
Color
:texture : Structure: Consistency: Roots
: Dry :Moist:analysis :
:
(moist)
description~
Date: August 13, 1976
Soil type: gravelly silt-loam
Soil series: Felan (Klages and others 1976)
Soil subgroup: andic cryochrept (Klages and others 1976)
Family: loamy-skeletal, mixed (Klages and others 1976)
Elevation: - 1970 m
Slope: -60%
Aspect: east
Parent material: limestone (Klages and others 1976)
Habitat type: Abies lasiocarpa/Clintonia uniflora
(Pfister and others 1977)
1.0-40.0
2.0-0.0
02
B2
3.0-2.0
01
1.0
Thickness
- - - - em -
Horizon: Depth
Table 13.--Soil
:
pH=6.1
%M=62.5
(at 14.5 em
depth)
Reaction
Average Cation Exchange Capacity of Coram Soils
Cation exchange
Depth
(me/100 g)
(em)
13.10
9.05
9.63
8.78
9.23
8.23
9.08
9.63
13.53
6.25
0-5
5-10
10-15
15-20
20-25
25-30
30-35
35-40
40-45
45-50
9.65
Average
Table 14.--Characteristics of Coram soils: particle
density~
particle
size~
organic
content
PARTICLE CHARACTERISTICS
Particle weight 1
>1 mm
- - - -
Particle size
<1 mm
<1 mm
>1 mm
- g/cm 3
Percent
0.451
0.830
64.55
35.45
ORGANIC CONTENT
Block
Soil depth
20-25 em
0-5 em
50-55 em
14.59
7.39
12.74
12.64
3.57
4.26
5.06
5.92
1. 94
21
8. 64
9.41
7.76
17.73
6.00
7.33
10.86
5.16
4.56
4.93
13.43
3.23
13
9.15
11. 29
5.33
10.71
3.62
5. 79
3.87
5.24
2.60
2.62
3.80
5.63
23
17.53
10.98
13.86
12.12
5.24
7.91
6.53
7.45
2.28
2.34
3.99
3. 09
11
1Average
particle density
2.56 g/cm 3 •
36
2.76
1. 96
2.20
APPENDIXC
Average Elemental Content of Coram Forest Soil Samples
37
Table 15.--Average elemental content of 0.002 N H2 S0 4 soil extract from
by depth and plot~ all months combined (pretreatment)
Plot: Sub
+
H
Ca
Nolar
Cu
Fe
K
Element
Mg : Mn
Na
N
Coram~
1.1g/g~
as
P0 4
Zn
May and October 1973
0-5 ern
11
1
2
3
4
-6
0. 74_5
0.22_6
0.66_5
0.12
1089
914
1283
1166
2
2
3
2
24
23
33
25
291
282
375
329
113
124
144
114
83
166
93
100
13
18
19
23
1766
1920
2608
2203
101
77
107
105
3
2
2
2
21
1
2
3
4
-5
0.20_5
0.12_5
0.12_6
0.64
991
1124
1160
1257
3
3
2
2
29
26
25
20
234
251
285
319
102
127
147
153
96
103
81
89
12
17
12
12
1644
1780
1953
2843
so
74
71
95
3
2
2
2
13
1
2
3
4
-6
0.78_5
0.25_5
0.14_5
0.36
1277
1072
1290
1224
2
3
3
3
20
27
33
42
240
193
288
254
106
133
96
104
82
93
76
89
13
15
11
14
2280
2313
1825
2016
84
94
74
86
2
2
2
2
23
1
2
3
4
-5
0.39_5
0.17_5
0.53_5
0.34
1082
1098
1035
1058
3
2
2
2
20
17
18
27
257
255
208
240
103
91
105
117
141
132
194
133
14
14
16
9
3158
2229
2935
2120
70
46
41
84
2
1
2
2
14
24
5
5
-6
0.96_5
0.29
1203
1281
3
2
24
19
292
228
124
127
96
115
12
14
2471
2046
56
82
1
1
20-25 em
--11
1
2
3
4
-6
0.99_5
0.19_5
0.11_6
0.98
725
698
850
857
2
3
3
3
44
36
45
30
160
144
247
196
69
67
87
78
23
38
33
27
22
25
29
31
648
702
1023
827
53
43
29
25
1
2
1
1
21
1
2
3
4
-5
0.18_5
0.14_5
0.15_5
0.12
750
870
931
775
3
3
3
3
29
23
31
27
150
189
172
180
78
92
126
105
33
38
21
26
14
22
14
15
832
1285
973
962
21
21
30
25
1
1
1
1
13
1
2
3
4
-5
0.10_5
0.26_6
0.96_5
0.26
876
865
1022
879
3
3
3
3
30
32
46
49
135
119
139
146
74
118
77
76
18
39
15
13
15
15
15
18
644
1140
766
706
38
43
28
29
1
1
1
1
23
1
2
3
4
-5
0.26_5
0.20_5
0.22_6
0.44
827
594
757
793
3
3
2
3
20
20
25
32
157
131
131
149
63
46
62
74
51
42
44
40
19
20
21
14
1077
1154
1289
1012
24
5
22
45
1
1
1
1
14
24
5
5
-5
0.17_5
0.29
1041
853
3
3
46
26
185
149
103
92
18
33
14
17
1044
932
23
34
1
1
(Cont.)
38
Table 15.--Average elemental content of 0. 002 N H2 S0 4 soil extract from
by depth and
Plot : Sub
H+
plot~
Ca
Coram~
~g/g~
as
all months combined (pretreatment)--Continued
Cu
Fe
K
Element
Mg
Mn
Na
N
P04
Zn
Molar
May and October 1973 (continued)
50-55 em
1
2
3
4
-6
0.71_5
0.14_6
0.96_5
0.10
588
640
591
596
3
3
21
1
2
3
4
-5
0.24_5
0.29_5
0.14_5
0.19
13
1
2
3
4
23
14
24
11
3
27
28
38
22
87
105
130
102
63
79
81
77
14
17
16
17
15
19
19
22
310
337
615
402
29
20
23
19
1
1
1
1
694
682
778
656
3
3
3
3
25
22
39
26
147
102
120
130
84
75
133
78
19
15
14
15
16
12
11
14
485
556
719
486
20
18
22
15
1
1
1
1
-6
0.73_5
0.10_6
0.59_5
0.15
910
938
1372
976
3
3
3
3
42
29
54
67
115
85
102
107
87
99
82
68
18
14
10
8
13
14
13
13
582
445
648
631
15
18
12
21
1
1
1
1
1
2
3
4
-5
O.I3_5
0.37_5
0.3I_s
0.24
657
430
627
673
3
3
3
3
17
I9
20
2I
127
76
93
100
63
60
67
63
22
I9
30
45
13
li
I7
I4
535
4I9
587
581
14
9
I3
27
I
I
I
I
5
5
-5
O.IO_s
O.I7
14I8
806
3
3
58
23
149
86
99
105
I2
2I
I4
15
796
593
I6
16
0
0
3
May I974
0-5 em
li
I
2
3
4
-6
0.63_5
0.16_6
0.98_5
0.10 .
743
727
1005
995
2
2
2
2
2I
22
18
15
2I9
198
350
282
76
77
124
96
4I
85
55
42
IO
I6
14
16
976
3ISO
208I
I422
85
54
70
57
2
2
I
I
2I
I
2
3
4
-5
O.IS_s
0.12_6
0.84_6
0.89
1I85
14I8
1564
I290
4
4
4
3
64
51
38
21
308
274
249
233
I 57
ISO
167
I86
I48
ISI
87
75
IO
10
IO
IO
IS 54
2303
I982
1885
174
168
82
68
6
4
2
2
I3
I
2
3
4
-6
0.38_5
0. 46-6
0. 95-5
0.37
IIOS
658
1I87
I042
2
2
2
2
27
43
4I
35
431
162
576
209
160
80
90
87
63
56
42
85
16
18
I9
I8
1105
IOSl
1439
I709
70
6I
63
43
1
2
1
2
23
I
2
3
4
-6
0.69_6
0.67_5
0.27_6
0.88
1I98
I204
957
1047
3
3
3
3
23
27
34
33
257
24I
206
2IO
I33
96
83
12I
I27
79
I 58
65
13
IS
18
9
2268
2308
2791
144I
74
47
39
7I
1
I
2
2
14
24
5
5
-6
0.15_5
O.IO
1185
957
2
2
44
40
279
215
I09
I09
72
62
Il
IS
1562
ISI4
63
40
I
I
(Cant.)
39
Table 15.--Average elemental content of 0.002 N H2 S04 soil extract from
Coram~
as 1,1g/g_,
by depth and plot_, all months combined (pretreatment)--Continued
Plot : Sub
+
H
Ca
Molar
Cu:
Fe
K
Element
Mn
Mg
Na
N
P0 4
Zn
May 1974 (continued)
20-25 em
..
11
1
2
3
4
-6
0.72_5
0.13_6
0.96_6
0.61
746
647
809
856
2
2
2
2
36
24
15
15
155
129
190
237
79
65
90
90
10
19
10
8
15
21
17
20
598
927
706
823
41
18
16
14
1
1
1
1
21
1
2
3
4
-6
0.95_5
0.11_5
0.12_6
0.83
801
743
1128
673
4
4
4
4
60
53
66
50
196
159
175
201
109
87
180
123
36
31
22
21
14
20
11
13
869
1100
1014
882
92
105
40
46
1
1
1
1
13
1
2
3
4
-6
0.97_5
0.24_6
0.96_5
0.18
878
722
1053
923
2
2
1
2
28
34
30
27
259
119
250
141
136
92
72
78
26
27
10
9
26
19
21
22
1460
710
710
749
26
32
13
8
1
1
1
1
23
1
2
3
4
-6
0.98_6
0.54_6
0.79_6
0.62
707
593
821
774
3
3
3
3
31
27
32
37
162
136
95
179
60
47
61
71
27
18
18
20
17
17
21
11
904
925
1525
687
26
7
25
47
0
0
5
5
-6
0.24_6
0.63
1029
716
2
2
78
31
209
165
82
98
13
33
15
19
773
897
21
18
1
1
·-
14
24
0
0
50-55 em
11
1
2
3
4
-6
0.70_5
0.14_6
0.63_6
0.70
508
509
540
505
2
2
3
2
19
19
19
14
72
90
100
82
64
57
86
64
6
9
10
8
15
15
13
14
326
402
476
323
14
17
14
7
0
0
1
1
21
1
2
3
4
-6
0.59_5
0.14_5
0.10_5
0.10
530
483
911
482
5
4
4
4
36
26
97
25
86
85
136
101
88
61
221
74
13
14
13
12
11
11
11
10
426
425
960
459
33
26
23
19
1
1
1
1
13
1
2
3
4
-6
0.89_5
0.11_6
0.80_6
0.49
889
730
1577
1419
2
2
1
1
25
28
40
32
114
90
106
193
79
111
76
112
10
13
8
7
17
16
20
19
491
455
799
551
11
7
7
4
1
1
0
0
23
1
2
3
4
-6
0.92_6
0.61_6
0.89_6
0.55
572
451
642
619
3
3
3
3
27
19
24
24
98
73
84
93
63
68
88
61
13
7
16
23
13
10
17
11
442
292
540
389
19
11
19
35
0
0
0
0
14
24
5
5
-6
0.29_6
0.52
1407
764
2
2
85
30
169
95
92
91
7
32
15
20
769
725
13
14
1
1
(Cont.)
40
11g/g~
Table 15.--AvePage elemental content of 0.002 N H2 S0 4 soil extPact from Coram~ as
by depth and plot_, all months combined (pretreatment)--Continued
Plot: Sub
H
+
-Ca
Cu
Fe
K
Element
Mg
Mn
Na
N
P0 4
Zn
Molar
All depths, plots, and months combined
Average
0.10- 5
895
3
36
184
98
38
15
1078
40
1
S.D.
0.14-S
426
1
35
177
68
47
6
1035
54
1
7.70
3.00
Percent
nutrient
balance
Total cations
Total anions
70.43
0.21
2.85 14.50
1270
593
41
1. 21
0.08
Stark, Nellie M.
1979. Nutrient losses from timber harvesting in a larch/
Douglas-fir forest.
USDA For. Serv. Res. Pap. INT-231, 41 p.
Intermt. For. and Range Exp. Stn., Ogden, Utah 84401.
Nutrient levels as a result of experimental clearcutting,
shelterwood cutting, and group selection cutting--each with
three levels of harvesting intensity--were studied in a larchfir forest in northwest Montana, experimentally logged with a
skyline system. None of the treatments altered nutrient levels
in an intermittent stream, nor were excessive amounts of nutrients lost in soil below the root zone. Under conditions on
this site, skyline logging did not result in surface erosion or
nutrient losses that would affect forest management.
KEYWORDS: Harvest, nutrient cycling, nutrient loss, water
quality.
Stark, Nellie M.
1979. Nutrient losses from timber harvesting in a larch/
Douglas-fir forest.
USDA For. Serv. Res. Pap. INT-231, 41 p.
Intermt. For. and Range Exp. Stn., Ogden, Utah 84401.
Nutrient levels as a result of experimental clearcutting,
shelterwood cutting, and group selection cutting--each with
three levels of harvesting intensity--were studied in a larchfir forest in northwest Montana, experimentally logged with a
skyline system. None of the treatments altered nutrient levels
in an intermittent stream, nor were excessive amounts of nutrients lost in soil below the root zone. Under conditions on
this site, skyline logging did not result in surface erosion or
nutrient losses that would affect forest management.
KEYWORDS: Harvest, nutrient cycling, nutrient loss, water
quality.
'!!ru.s.
GOVERNMENT PRINTING OFFICE: 1979-0-677-019/ 1 8
'
Headquarters for the Intermountain Forest and
Range Experiment Station are in Ogden, Utah.
Field programs and research work units are
maintained in:
Billings, Montana
Boise, Idaho
Bozeman, Montana (in cooperation with
Montana State University)
Logan, Utah (in cooperation with Utah State
University)
Missoula, Montana (in cooperation with
University of Montana)
Moscow, Idaho (in cooperation with the
University of Idaho)
Provo, Utah (in cooperation with Brigham
Young University)
Reno, Nevada (in cooperation with the
University of Nevada)
FOREST RESIDUES UTILIZATION
RESEARCH AND DEVELOPMENT PROGRAM
,(